The present invention relates to a copying apparatus. More particularly this invention concerns a fuser assembly for such an apparatus.
A copying apparatus of the xerographic type typically has a housing provided with conveyor means which define a transport path. An imaging arrangement, typically in the form of a selenium-coated drum and appropriate optical and toner-applying equipment, is provided at an upstream imaging station along this path, and a fusing assembly, typically comprising a radiant heater, is provided at a fusing station downstream of the path. The conveyor means transports a copy sheet along the path, so that the imaging equipment can form a toner image on the copy sheet and thereafter the downstream fusing assembly can fuse this image. Such an arrangement is described in U.S. Pat. No. 3,219,326 whose entire disclosure is herewith fully incorporated by reference.
It is standard in such systems to form the conveyor path underneath the fuser assembly of a heat-resistant belt on which the copy sheet lies as it is passed through the fuser station. Thus, the radiant heater is directed downwardly at the copy sheet at a slight spacing above the belt on which it lies.
A typical problem with such assemblies is that it is necessary frequently to service the fuser assembly. As the fuser heater itself is frequently a quartz heater that shines through a transparent window onto the copy sheet, so that the copy sheet cannot directly contact the heater, it is necessary to clean this window. Furthermore, paper jams, which can occur anywhere along the conveyor path, frequently occur at the fusing station where the copy is not pinched between rollers or the like, but where it is merely lying on the transport belt so that an upturned edge or corner can catch on surrounding structure and jam in the machine.
Thus, it is frequently necessary to open up the machine and gain access to the conveyor path at the fuser station, and to gain access to the fuser heater itself. This can be done simply by leaving the edge of the conveyor path exposed, and by making the fuser heater removable in a direction perpendicular to the direction of travel of the sheet along the path. As suggested in the above-mentioned patent, it is also possible to mount the entire fuser assembly on rails extending perpendicular to the above-mentioned direction of travel. Thus, this entire fuser assembly can be slid, drawer-fashion, out of the machine for servicing of the fuser parts or clearing of a paper jam.
Such an arrangement has certain advantages, but nonetheless leaves the fuser assembly, when pulled out of the machine, in a position where servicing it is still somewhat difficult. What is more access can only be gained to the conveyor path, which is exposed when the fuser assembly is pulled out, by reaching over and past the fuser assembly. Finally, if the paper jam occurs directly under the fuser, such transverse pulling-out of the fuser assembly will only worsen the paper jam, crumpling the jammed paper up under the fuser and perhaps even damaging the delicate mechanism of the arrangement.